Method of Surgical Planning

ABSTRACT

A method of pre-operatively forming a surgical splint configured to receive a patient&#39;s dentition can include combining a  3 -D facial computer model and a  3 -D dental computer model. The method includes the step of obtaining a  3 -D facial computer model of at least the patient&#39;s maxilla, mandible, and dentition from a CT scanner and the step of obtaining a  3 -D dental computer model of the patient&#39;s dentition with an optical scanner. The  3 -D dental computer model is then combined with the  3 -D facial computer model to form a composite virtual model. The composite virtual model can be manipulated into a planned post-operative shape, and a surgical splint can be custom constructed to match the planned post-operative shape. The surgical splint can be configured to receive the patient&#39;s dentition.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 13/788,742,filed Mar. 7, 2013, which claims the benefit of U.S. ProvisionalApplication No. 61/648,226, filed May 17, 2012, the contents of both ofwhich are hereby incorporated by reference as if set forth in theirentirety herein.

BACKGROUND

Surgical planning for orthognathic surgery traditionally combinesvarious diagnostic methods to create a surgical plan and/or to constructa surgical splint that can transfer the surgical plan to the patient inthe operating room. According to more recent methods, a 3-D computedtomography (CT) model of the patient's skull including the patient'smandible, maxilla, and dentition is obtained using a CT scanner. Whilethe CT scanner provides a good representation of the patient's bonestructure, it is not capable at times of accurately representing thepatient's dentition (i.e. teeth). For example, the dentition representedin the CT model may be obscured or otherwise include “artifacts” due toorthodontic metal brackets, dental fillings, or prosthesis on or nearthe patient's dentition.

To create a 3-D computer model having a good representation of both thepatient's bone structure and the patient's dentition, a dental computermodel of the patient's dentition is typically obtained by scanning anegative of an impression (i.e. a plaster cast) of the patient'sdentition with a laser scanner or a CT scanner. Because a plaster castof the dentition, and not the dentition themselves is scanned, thevirtual dental model is not obscured or otherwise “scattered” due to themetal brackets, fillings, or prosthesis. The virtual dental model isthen combined with the CT model of the patient's skull to thereby form acomposite computer model that has virtual dentition void of anyartifacts. The composite computer model is used to create the surgicalplan and/or surgical splint.

To align the dental computer model with the dentition of the CT model,metal fiduciary markers are currently used during both the CT scan ofthe patient's skull and the scan of the plaster cast. The fiduciarymarkers of the dental computer model are then aligned with the fiduciarymarkers of the CT model to form the composite computer model. While thecurrent method is capable of forming a composite computer model that isused to create an orthognathic surgical plan and/or surgical splint, themethod is time consuming. Moreover, there remains a desire for moreaccurate surgical plans and/or surgical splints than those currentlyprovided.

SUMMARY

A method of pre-operatively forming a surgical splint configured toreceive a patient's dentition can include combining a 3-D facialcomputer model and a 3-D dental computer model. The method includes thestep of obtaining a 3-D facial computer model of at least the patient'smaxilla, mandible, and dentition. The 3-D facial computer model includesfirst virtual dentition, wherein at least a portion of the first virtualdentition of the 3-D facial computer model has a first virtual surfacegeometry that defines at least one first fiduciary marker. The methodfurther includes the step of obtaining a 3-D oral scan of a surfacegeometry of the patient's dentition so as to produce second virtualdentition. At least a portion of the second virtual dentition has asecond surface geometry that defines at least one second fiduciarymarker that corresponds to the at least one first fiduciary marker ofthe 3-D facial computer model. The second fiduciary marker can bealigned with the first fiduciary marker. After the alignment step, thefirst virtual dentition of the 3-D facial computer model can be replacedwith the second virtual dentition to form a composite 3-D virtual model.The composite 3-D virtual model can have third virtual dentition in aplanned post-operative configuration. A surgical splint can be customconstructed to match the planned post-operative shape. The surgicalsplint can have a negative impression of at least a portion of the thirdvirtual dentition.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofexample embodiments, are better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,the drawings show embodiments that are presently preferred. Theinvention is not limited, however, to the specific instrumentalitiesdisclosed in the drawings.

FIG. 1A is a perspective view of a composite 3-D virtual model of apatient's skull including a 3-D virtual representation of the patient'smaxilla, mandible and dentition, the maxilla and mandible beingpositioned into a desired post-operative shape;

FIG. 1B is a top perspective view of a final surgical splint that isconfigured to align the patient's maxilla and mandible in the desiredpost-operative shape, the final surgical splint is custom constructedpre-operatively using the composite computer model of FIG. 1A;

FIG. 1C is a bottom perspective view of the final surgical splint shownin FIG. 1B;

FIG. 1D is a bottom perspective view of an intermediate surgical splintthat is configured to align the patient's maxilla in its desiredpost-operative shape prior to the mandible being aligned in its desiredpost-operative shape, the intermediate surgical splint is constructedpre-operatively using the composite computer model of FIG. 1A;

FIG. 1E is a bottom perspective view of the intermediate surgical splintshown in FIG. 1D;

FIGS. 2A-2E illustrate steps of a method of creating the composite 3-Dvirtual model shown in FIG. 1A in accordance with an embodiment;

FIGS. 3A-3E illustrate steps of a method of creating the composite 3-Dvirtual model shown in FIG. 1A in accordance with another embodiment;

FIG. 4A is a front elevation view of a composite 3-D virtual model in apre-operative shape, the composite 3-D virtual model having a virtualmaxilla, a virtual mandible, and virtual dentition;

FIG. 4B is a side elevation view of the composite 3-D virtual modelshown in FIG. 4A;

FIG. 4C is a front elevation view of the composite 3-D virtual modelshown in FIG. 4A in an intermediate shape, the virtual maxilla beingrepositioned into its post-operative shape while the virtual mandibleremains in its pre-operative shape;

FIG. 4D is a side elevation view of the 3-D composite computer shown inFIG. 4C;

FIG. 4E is a front elevation view of the composite 3-D virtual modelshown in FIG. 4C including a virtual intermediate splint that receivesthe virtual dentition when the virtual maxilla is in its post-operativeshape and the virtual mandible is in its pre-operative shape;

FIG. 4F is a front elevation view of the composite 3-D virtual modelshown in FIG. 4C in a final post-operative shape, the virtual mandiblebeing repositioned into its post-operative shape along with the virtualmaxilla;

FIG. 4G is aside elevation view of the composite 3-D virtual model shownin FIG. 4F;

FIG. 4H is a front elevation view of the composite 3-D virtual modelshown in FIG. 4F including a virtual final splint that receives thevirtual dentition when both the virtual maxilla and the virtual mandibleare in their post-operative shape;

FIG. 5 is a flow chart that describes a method of custom constructing asurgical splint in accordance with an embodiment; and

FIG. 6 is a flow chart that describes a method of custom constructing asurgical splint in accordance with another embodiment.

DETAILED DESCRIPTION

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “right”, “left”, “lower” and “upper”designate directions in the drawings to which reference is made. Thewords “inner” or “distal” and “outer” or “proximal” refer to directionstoward and away from, respectively, the geometric center of the implantand related parts thereof The words, “anterior”, “posterior”,“superior,” “inferior,” “medial,” “lateral,” and related words and/orphrases designate preferred positions and orientations in the human bodyto which reference is made and are not meant to be limiting. Theterminology includes the above-listed words, derivatives thereof andwords of similar import.

Referring to FIGS. 1A-1C, a first orthognathic surgical splint 10 can becustom constructed for an individual patient by creating a composite 3-Dvirtual model 14 of the patient's skull including at least a virtualrepresentation of the patient's maxilla, mandible, and dentition.Therefore, the composite 3-D virtual model 14 can include a virtualmaxilla 18, a virtual mandible 22, and virtual dentition 26. Using thecomposite 3-D virtual model 14, the surgical splint 10 can be customconstructed prior to the surgical operation (i.e. pre-operatively) tomatch or otherwise conform to a desired and planned post-operative shapeof the patient's skull.

As will be described in reference to FIGS. 2A-2E, the composite 3-Dvirtual model 14 combines a 3-D dental computer model 30 obtained in acomputer from an optical scan of a surface geometry of the patient'sdentition with a separate 3-D facial computer model 34 obtained in thecomputer from a scan of the patient's skull. The 3-D dental computermodel 30 and the 3-D facial computer model 34 are combined to therebyform the composite 3-D virtual model 14 that includes detailed boneinformation from the 3-D facial computer model 34 and detailed dentitioninformation from the 3-D dental computer model 30.

Once created, the composite 3-D virtual model 14 can be manipulated intoa desired post-operative shape by for example, adjusting the virtualmaxilla 18 and/or the virtual mandible 22 of the composite 3-D virtualmodel 14 relative to the other to correct craniofacial/maxillofacialdeformities and/or a cosmetic defect. Using the composite 3-D virtualmodel 14 after it has been manipulated into the planned post-operativeshape, the orthognathic surgical plan and/or the surgical splint 10 canthen be custom constructed to match the planned post-operative shape.For example, a computer model or virtual splint can be created inconjunction with the composite 3-D virtual model 14 to match the plannedpost-operative shape of the patient's skull. That is, a computer modelor virtual splint can be created so as to be configured to receive thevirtual dentition 26 after the virtual maxilla 18 and/or the virtualmandible 22 have been repositioned. Information from the computer modelor virtual splint can then be transferred to a rapid prototyping machinewhere the actual surgical splint is fabricated. It should beappreciated, that the planned post-operative shape of the patient'sskull can be substantially similar to the pre-operative shape of thepatient's skull and that the surgical plan and/or surgical splint 10 canbe constructed to aid in the correction of a portion of the patient'sskull other than the maxilla and mandible. For example, theatrical planand/or surgical splint 10 can be constructed to aid in the replacementof a tooth.

As shown in FIGS. 1B and 1C, the surgical splint 10 can include an uppersurface 40 and a lower surface 44. The upper surface 40 can beconfigured to receive the upper dentition of the patient such as atleast a portion of the upper dentition, and the lower surface 44 can beconfigured to receive the lower dentition of the patient such as atleast a portion of the lower dentition when the patient's mandible andmaxilla are in their post-operative shape or positions so as to definethe post-operative shape of the patient's skull. That is, the uppersurface 40 of the surgical splint 10 defines a negative impressionhaving contours that correspond to the contours of the upper dentitionof the patient when the upper dentition are received by the negativeimpression, and the lower surface 44 defines a negative impressionhaving contours that correspond to the contours of the lower dentitionof the patient when the lower dentition are received by the negativeimpression, and when both the patient's maxilla and the patient'smandible are properly positioned. Therefore, the upper surface 40 willmatch the upper dentition of the patient, and the lower surface 44 willmatch the lower dentition of the patient when both the patient's maxillaand the patient's mandible have been moved into their desiredpost-operative shape or positions. In this way, the surgical splint 10acts as a guide for the orthognathic surgical plan such that the maxillaand the mandible can more easily be aligned into their desiredpost-operative positions during the surgery.

In certain cases and in reference to FIGS. 1C and 1D, a secondorthognathic surgical splint 50 may be desired. For example, in caseswhere both the maxilla and the mandible of the patient are to berepositioned into a post-operative position or shape, the maxilla can berepositioned and affixed in its post-operative position prior to themandible being repositioned. The surgical splint 50 can be configured toensure that the repositioned maxilla is properly aligned into itspost-operative position or shape prior to being affixed into positionwith bone screws.

Therefore, the surgical splint 50 can include an upper surface 54configured to receive the upper dentition of the patient such as atleast a portion of the dentition, and a lower surface 58 configured toreceive the lower dentition of the patient such as at least a portion ofthe dentition when the patient's maxilla is in its post-operative shapeor position, and the patient's mandible is in its pre-operative shape orposition. That is, the upper surface 54 defines a negative impressionhaving contours that correspond to the contours of the upper dentitionof the patient when the upper dentition are received by the negativeimpression, and the lower surface 58 defines a negative impressionhaving contours that correspond to the contours of the lower dentitionof the patient when the lower dentition are received by the negativeimpression, and when the patient's maxilla is properly repositioned andprior to the mandible being repositioned. Therefore, the upper surface54 will match the upper dentition of the patient, and the lower surface58 will match the lower dentition of the patient when the patient'smaxilla has been moved into its desired post-operative shape orposition. In this way, the surgical splint 50 also acts as a guide forthe orthognathic surgical plan. Once the maxilla is affixed to theskull, the mandible can be repositioned using the surgical splint 10. Inthis way, the surgical splint 10 can be considered a final surgicalsplint and the surgical splint 50 can be considered an intermediatesurgical splint. It should be appreciated, however, that the mandiblecan be repositioned prior to the repositioning of the maxilla.Therefore, in cases where both the mandible and the maxilla are to berepositioned, the mandible can be repositioned first using theintermediate surgical splint 50, and the maxilla can be repositionedsecond using the final surgical splint 10.

Both the surgical splint 10 and the surgical splint 50 can bemanufactured out of a plastic, such as acrylic. The surgical splints 10and 50 can be machined or otherwise fabricated using a rapid prototypingmachine such as a stereolithographic apparatus (SLA mathine). The SLAmachine can fabricate the surgical splints 10 and 50 based on thecomputer models or virtual splints created using the composite 3-Dvirtual model 14. It should be appreciated, however, that the surgicalsplints 10 and 50 can be manufactured out of any material as desired,and that the surgical splints 10 and 50 can be manufactured using anymanufacturing method as desired.

FIGS. 2A-2E illustrate a method of forming the composite 3-D virtualmodel 14 used to create the surgical splints (i.e. surgical splints 10and 50). The method can include all or some of the steps schematicallyrepresented as steps 2A, 2B, 2C, 2D, and 2E. To form the composite 3-Dvirtual model 14 and in reference to steps 2A and 2C, the 3-D facialcomputer model 34 and the 3-D dental computer model 30 can be obtainedin a computer using respective scanning devices.

In step 2A, the 3-D facial computer model 34 can be obtained by scanningthe patient's skull using any suitable technology. For example, the 3-Dfacial computer model of the patient's skull can be obtained by scanningthe patient's skull using any suitable scanner 60, such as a CT orcoronal view cone beam CT scan (CBCT) scanner as illustrated. It shouldbe appreciated, however, that the 3-D facial computer model 34 may beobtained using technology other than a CT scanner, such as a laserscanning machine, an optical scanning machine, or an MRI machine. Inoperation, scanner 60 can be used to scan the patient's skull. Scanneddata obtained from the scanner 60 can then be downloaded or transferredto a computer. In the computer, the 3-D facial computer model 34representing the patient's skull is created from the scanned data usingany suitable software capable of processing and editing images.

As shown in FIG. 2B, the 3-D facial computer model 34 can include atleast a virtual maxilla 70, a virtual mandible 74, and virtual dentition78. The virtual maxilla 70, virtual mandible 74, and virtual dentitionare virtual representations of the patient's actual maxilla, actualmandible, and actual dentition. The virtual dentition 78 of the 3-Dfacial computer model 34, however, can be obscured or otherwise“scattered” (i.e. include artifacts) due to orthodontic metal brackets,dental fillings, or prosthesis that are proximate to the patient'sactual dentition during the scan by the scanner 60. While the virtualdentition 78 may not have the desired accuracy, at least a portion 82 ofthe virtual dentition 78 has a first virtual surface geometry thatdefines a first fiduciary marker 86 that is substantially unobscured bythe artifacts. That is, the at least a portion 82 of the virtualdentition 78 can have the necessary accuracy to define a point ofreference so as to create a fiduciary marker 86 that can be later usedto align the 3-D dental computer model 30 with the 3-D facial computermodel 34. It should be appreciated, that the at least a portion 82 canbe any portion of the virtual dentition 78. It should be furtherappreciated, that the virtual dentition 78 can have a first virtualsurface geometry that defines any number of first fiduciary markers 86.For example, the virtual dentition 78 can have a first virtual surfacegeometry that defines at least three first fiduciary markers 86.

In step 2C, the 3-D dental computer model 30 of the patient's dentitioncan be obtained from a 3-D optical intraoral scan or otherwiseintraorally imaging the patient's actual dentition with an intraoralscanner 64 such as with an optical scanner as illustrated. The scanneddata can then be downloaded or transferred to a computer such as thesame computer as the 3-D facial computer model 34. In the computer, the3-D dental computer model 30 representing the patient's dentition iscreated using any suitable software capable of processing and editingimages.

As shown in FIG. 2D, the 3-D dental computer model 30 more accuratelydepicts the patient's actual dentition as compared to the virtualdentition 78 depicted in the 3-D facial computer model 34. That is, the3-D dental computer model 30 is substantially free from the artifactsthat are produced in the 3-D facial computer model 34 by the scanner 60.As shown in FIG. 2D, the 3-D dental computer model 30 includes secondvirtual dentition 88 that have a second virtual surface geometry thatdefines at least one second fiduciary marker 90 that corresponds to theat least one first fiduciary marker 86 of the virtual dentition 78 ofthe 3-D facial computer model 34. In particular, the second virtualsurface geometry of the virtual dentition 88 of the 3-D dental computermodel 30 can define a second fiduciary marker 90 that corresponds toeach first fiduciary marker 86 of the virtual dentition 78 of the 3-Dfacial computer model 34,

Unlike the scanner 60, the scanner 64 is configured to obtain 3-Dsurface information of the patient's dentition at a very high degree ofaccuracy and substantially without any artifacts. The scanner 64 is ableto generate the 3-D surface information by moving the scanner directlyover the patient's actual dentition. The scanner 64 obtains coordinatesof points or pixels on the surface of the dentition being scanned, whichare processed in a computer to calculate the surface configuration ofthe dentition and subsequently form the 3-D dental computer model 30.The scanner 64 can include an oscillating microelectromechanical systems(MEMS) mirror and a light source that emits a laser beam toward theoscillating MEMS mirror. The oscillating MEMS mirror reflects theemitted laser beam toward the surface of the patient's dentition. Thesurface of the patient's dentition then reflects the emitted laser beamback to a receiver of the scanner 64. A processing unit of the scanner64 records timing parameters of the emitted laser beam and reflectedlaser beam, and oscillation angles of the oscillating MEMS mirror. Theprocessing unit then computes the 3-D surface configuration of thepatient's dentition and subsequently forms the 3-D dental computer model30. It should be appreciated, however, that the 3-D dental computermodel 30 can be obtained using any scanner capable of accuratelycreating an image of the patient's dentition that is substantially freefrom artifacts.

In step 2E, the 3-D dental computer model 30 and the 3-D facial computermodel 34 can be combined to form the composite 3-D virtual model 14. Themodels 30 and 34 can be combined by aligning the at least one secondfiduciary marker 9C) of the virtual dentition 88 of the 3-D dentalcomputer model 30 with the at least one first fiduciary marker 86 of thevirtual dentition 78 of the 3-D facial computer model 34. The virtualdentition 78 of the 3-D facial computer model 34 are thus replaced withthe more accurate virtual dentition 88 of the 3-D dental computer model30 thereby creating a computer model that more accurately representsboth the bony structure and the dentition of the patient. Therefore, thevirtual maxilla 18, the virtual mandible 22, of the composite 3-Dvirtual model 14 are the same as the virtual maxilla 70, and the virtualmandible 74 of the 3-D facial computer model 34, and the virtualdentition 26 of the composite 3-D virtual model 14 are the same as thevirtual dentition 88 of the 3-D dental computer model 30. It can also besaid, however, that the virtual dentition 26 of the composite 3-Dvirtual model are third virtual dentition 26. Because the 3-D dental andfacial computer models 30 and 34 are aligned using first and secondfiduciary markers 86 and 90 that are defined by the virtual surfacegeometries of the virtual dentition of the 3-D dental and facialcomputer models 30 and 34, the models 30 and 34 are capable of beingaligned without using metal fiduciary markers.

The combining step shown in FIG. 2E can be performed by a computerprogram having an algorithm that is capable of matching the fiduciarymarkers 86 and 90. While the computer program may be able tosubstantially align the fiduciary markers 86 and 90, some manualalignment may be required by the user by moving the virtual dentition 88of the 3-D dental computer model 30 relative to the virtual dentition 78of the 3-D facial computer model 34 with for example a computer mouse.It should be appreciated, however, that the fiduciary markers 86 and 90can he aligned using any method as desired. For example, the user maycompletely align the fiduciary markers 86 and 90 without the use of acomputer program as desired.

Once the composite 3-D virtual model 14 is created, the composite 3-Dvirtual model 14 can then be manipulated into a planned post-operativeshape as desired. For example, at least one of the virtual maxilla 18and the virtual mandible 22 can be repositioned relative to each otheror the remainder of the virtual skull into a desired shape or positionso as to properly align the third virtual dentition 26 of the composite3-D virtual model 14 into the desired post-operative configuration. Itcan also be said, that the third virtual dentition can be displaced intothe desired and planned post-operative configuration. Using the plannedpost-operative configuration of the virtual dentition 26 of thecomposite 3-D virtual model 14, the surgical splint(s) can be formed orotherwise fabricated pre-operatively so as to be able to receive thepatient's actual dentition after the patient's actual maxilla and/oractual mandible have been repositioned into the planned-post operativeshape. That is, the surgical splint(s) can be constructed to have anegative impression of a least a portion of the third virtual dentition26. In this way, the surgical splint(s) can be custom constructed tomatch the planned post-operative shape prior to the surgery and act as aguide during the surgical procedure.

FIGS. 3A-3E illustrate a method of forming the composite 3-D virtualmodel 14 in accordance with another embodiment. The method illustratedin FIGS. 3A-3E can include all or some of the steps of the methodillustrated in FIGS. 2A-2E and are schematically represented as steps3A, 3B, 3C, 3D, and 3E. As shown in FIGS. 3A-3E, to form the composite3-D virtual model 14 and in reference to steps 3A and 3C, the 3-D facialcomputer model 34 and the 3-D dental computer model 30 are obtainedusing respective scanning devices.

In step 3A, the 3-D facial computer model 34 is obtained in a similarmanner as described in step 2A of the method illustrated in FIGS. 2A-2E.Therefore as in Step 2A, the 3-D facial computer model 34 of thepatient's skull can be obtained in a computer by scanning the patient'sskull using any suitable scanner 60, such as a CT or CBCT scanner asillustrated. Also as in Step 2A, the 3-D facial computer model 34obtained by the scan includes at least the virtual maxilla. 70, thevirtual mandible 74, and first virtual dentition 78. As previouslydescribed, the first virtual dentition 78 of the 3-D facial computermodel 34 can be obscured or otherwise “scattered” (i.e. includeartifacts), however, at least a portion 82 of the first virtualdentition 78 can include a first virtual surface geometry that has thenecessary accuracy to define a first fiduciary marker 86.

In step 3C, the 3-D dental computer model 30 of the patient's dentitioncan be obtained in the computer by scanning or otherwise imaging anegative impression 160 of the patient's actual dentition with theoptical scanner 64 rather than directly scanning the patient's actualdentition as performed in step 2B of the method illustrated in FIGS.2A-2E.

in step 3C, the negative impression 160 of the patient's actualdentition can be formed using any conventional method. For example, thenegative impression 160 can be formed using plaster. It should beappreciated, however, that the impression 160 can be formed using anymethod as desired.

Once the negative impression 160 is formed, the optical scanner 64 canscan the impression 160 to thereby create the 3-D dental computer model30. As with the model created in step 2B, the 3-D dental computer model30 more accurately depicts the patient's actual dentition as compared tothe virtual dentition 78 depicted in the 3-D facial computer model 34.That is, the 3-D dental computer model 30 is substantially free from theartifacts that are produced in the 3-D facial computer model 34 by thescanner 60. The 3-D dental computer model 30 obtained in step B2 alsoincludes second virtual dentition 88 that have a second virtual surfacegeometry that defines at least one second fiduciary marker 90 thatcorresponds to the at least one first fiduciary marker 86 of the firstvirtual dentition 78 of the 3-D facial computer model 34.

In step 3E, the 3-D dental computer model 30 and the 3-D facial computermodel 34 can be combined to form the composite 3-D virtual model 14 inthe same manner described in relation to step 2E. That is, the models 30and 34 can be combined by aligning the at least one second fiduciarymarker 90 of the second virtual dentition 88 of the 3-D dental computermodel 30 with the at least one first fiduciary marker 86 of the firstvirtual dentition 78 of the 3-D facial computer model 34.

Now in reference to FIGS. 4A-4H, a method of custom constructingsurgical splints, such as surgical splints 10 and 50 using a compositecomputer model created using one of the methods described in FIGS. 2 and3 is illustrated. The method can be used to make both the intermediatesurgical splint 50 and the final surgical splint 10 or can be used tomake only one of the surgical splints 10 and 50 as desired. Therefore,the method can include all or some of the steps schematicallyrepresented in FIGS. 4A-4H.

As shown in FIGS. 4A and 4B, a composite 3-D virtual model 214 caninclude a virtual maxilla 218, a virtual mandible 222, and third virtualdentition 226. The composite 3-D virtual model 214 can be obtained usingany of the methods described in FIGS. 2A-2E and 3A-3E. As shown, thecomposite 3-D virtual model 214 originally represents the pre-operativeshape of the patient's skull. In the illustrated example, the composite3-D virtual model 214 indicates that the patient's dentition is notaligned and that as a result, the patient's maxilla and mandible need tobe translated and rotated. Though it should be appreciated, that thepatient's maxilla and/or mandible can be manipulated in any mannerdesired.

With continued reference to FIGS. 4A and 4B, first and second virtualosteotomies 230 and 234 can be performed on the virtual maxilla 218 andvirtual mandible 222 of the composite 3-D virtual model 214. As shown inFIGS. 4C and 4D the composite 3-D virtual model 214 can be manipulatedinto a desired intermediate shape. For example, the virtual maxilla 218can be repositioned into its desired post-operative shape or positionwhile the virtual mandible 222 remains in its pre-operative shape orposition to thereby define an intermediate shape of the skull. As shown,the virtual maxilla 218 can be rotated and advanced forward a desiredamount as illustrated to thereby reposition the virtual maxilla 218 intothe desired post-operative shape or position. It should be appreciated,however, that the virtual maxilla 218 can be repositioned in any mannernecessary to place the virtual maxilla 218 into its desiredpost-operative shape or position or configuration.

While the composite 3-D virtual model 214 is in its intermediate shape,and thus prior to repositioning the virtual mandible 222, a virtualintermediate surgical splint 240 can be created to match theintermediate shape of the composite 3-D virtual model 214, for exampleas shown in FIG. 4E. That is, the virtual intermediate surgical splint240 can be created such that the virtual intermediate surgical splint240 receives the third virtual dentition 226 when the virtual maxilla216 is in its post-operative shape or position and the virtual mandible222 is in its pre-operative shape or position. Using the data from thevirtual intermediate surgical splint 240 the physical or actualintermediate splint (i,e, surgical splint 50 shown in FIGS. 1C and 1D)can be fabricated on a rapid prototyping machine. In this way, theactual intermediate splint is fabricated to match the virtualintermediate splint. It can also be said, that the actual intermediatesplint is constructed to have a negative impression of at least aportion of the third virtual dentition 226 when the third virtualdentition are in an intermediate configuration. Therefore, the actualintermediate splint can be used during the surgery to reposition thepatient's actual maxilla into the desired post-operative shape orposition as planned on the composite 3-D virtual model 214.

As shown in FIGS. 4F and 4G the composite 3-D virtual model 214 can bemanipulated into a desired final or post-operative shape. For example,with the virtual maxilla 218 already repositioned into its desiredpost-operative shape or position or configuration, the virtual mandible222 can now be repositioned into its desired post-operative shape orposition or configuration to thereby define the final post-operativeshape of the skull. As shown, the virtual mandible can be rotated andadvanced forward a desired amount as illustrated to thereby repositionthe virtual mandible 222 into the desired post-operative shape orposition. It should be appreciated, however, that the virtual mandible222 can be repositioned in any manner necessary to place the virtualmandible 222 into its desired post-operative shape or position.

While the composite 3-D virtual model 214 is in its final orpost-operative shape, a virtual final surgical splint 244 can be createdto match the desired post-operative shape of the composite 3-D virtualmodel 214. That is, the virtual final surgical splint 244 can be createdsuch that the virtual final surgical splint 244 receives the thirdvirtual dentition 226 when both the virtual maxilla 216 and the virtualmandible 222 are in their post-operative shapes or positions orconfigurations. Using the data from the virtual final surgical splint244 the physical or actual final splint (i.e. surgical splint 10 shownin FIGS. 1B and 1C) can be fabricated on a rapid prototyping machine. Inthis way, the actual final surgical splint is fabricated to match thevirtual final surgical splint. It can also be said, that the actualfinal splint is constructed to have a negative impression of at least aportion of the third virtual dentition 226 when the third virtualdentition are in a final post-operative configuration. Therefore, theactual final surgical splint can be used during the surgery as a guideto reposition the patient's actual mandible into the desiredpost-operative shape or position as planned on the composite 3-D virtualmodel 214. It should be appreciated, however, that in some cases only asingle surgical splint may he desired to reposition the patient'smandible and/or the patient's maxilla. Moreover, it should beappreciated that a surgical splint may be custom constructed to be aguide for a surgical procedure that does not involve repositioning thepatient's maxilla and/or the patient's mandible. For example, a surgicalsplint may he custom constructed to be a guide for a surgical procedurethat requires the placement of a tooth implant.

With reference to FIG. 5, a method 300 of pre-operatively forming asurgical splint configured to receive a patient's dentition when thepatient's skull is in a desired post-operative shape can include steps304, 308, 312, 316, and 320. In step 304 a 3-D facial computer model ofat least the patient's maxilla, mandible, and dentition can be obtainedin a computer. The 3-D facial computer model can include first virtualdentition, and at least a portion of the first virtual dentition of the3-D facial computer model can have a first virtual surface geometry thatdefines at least one first fiduciary marker. In step 308, a 3-D dentalcomputer model of the patient's dentition that more accurately depictsthe patient's dentition as compared to the dentition depicted in the 3-Dfacial computer model is produced by obtaining a 3-D optical scan of asurface geometry of the patient's dentition. The 3-D dental computermodel can include second virtual dentition that can have a secondsurface geometry that defines at least one second fiduciary marker thatcorresponds to the at least one first fiduciary marker of the 3-D facialcomputer model. In step 312, the 3-D dental computer model and the 3-Dfacial computer model can be combined to form a composite 3-D virtualmodel by aligning the at least one second fiduciary marker of the 3-Ddental computer model with the corresponding at least one firstfiduciary marker of the 3-D facial computer model. In step 316, thecomposite computer model can be manipulated into a plannedpost-operative shape. In step 320 a physical surgical splint can bepre-operatively custom constructed to match the planned post-operativeshape, and the physical surgical splint can be configured to receive thepatient's dentition when the patient's skull is in the desiredpost-operative shape,

In step 304, the 3-D facial computer model can be obtained in a computerby scanning the patient's skull with a CT scanner. In step 308, the 3-Ddental computer model can be obtained in the computer by intraorallyimaging the patient's dentition. For example, the 3-D dental computermodel can be obtained by directly scanning the patient's dentition withan intraoral scanner, such as an optical scanner. In step 312, the 3-Ddental computer model and the 3-D facial computer model can be combinedwithout the use of metal fiduciary markers. In step 316 the compositecomputer model can be manipulated by repositioning at least one of thevirtual maxilla and the virtual mandible. The method of FIG. 5 canfurther include the step of creating a virtual surgical splint model tomatch the planned post-operative shape, and the step of customconstructing the surgical splint comprises fabricating the surgicalsplint to match the virtual surgical splint model.

With reference to FIG. 6, a method 400 of pre-operatively forming asurgical splint configured to receive a patient's dentition when thepatient's skull is in a desired post-operative shape can include steps404, 408, 412, 416, 418 and 420. In step 404 a 3-D facial computer modelof at least the patient's maxilla, mandible, and dentition can beobtained in a computer. The 3-D facial computer model can includevirtual dentition, wherein at least a portion of the virtual dentitionof the 3-D facial computer model has a first virtual surface geometrythat defines at least one first fiduciary marker. In step 408, a dentalimpression of the patient's dentition can be formed. In step 412, a 3-Ddental computer model of the patient's dentition can be obtained in acomputer by scanning the dental impression with an optical scanner. The3-D dental computer model can include second virtual dentition, whereinthe second virtual dentition of the 3-D dental computer model have asecond virtual surface geometry that defines at least one secondfiduciary marker that corresponds to the at least one first fiduciarymarker of the 3-D facial computer model. In step 416, the 3-D dentalcomputer model and the 3-D facial computer model can be combined to forma composite 3-D virtual model by aligning the at least one secondfiduciary marker of the 3-D dental computer model with the correspondingat least one first fiduciary marker of the 3-D facial computer model. Instep 418, the composite computer model can be manipulated into a plannedpost-operative shape. In step 420 a surgical splint can be customconstructed to match the planned post-operative shape. The surgicalsplint can be configured to receive the patient's dentition. In step416, the first virtual dentition of the 3-D facial computer model can becombined with the second virtual dentition of the 3-D dental computermodel without the use of metal fiduciary markers.

It should be noted that the illustrations and discussions of theembodiments shown in the figures are for exemplary purposes only, andshould not be construed limiting the disclosure. One skilled in the artwill appreciate that the present disclosure contemplates variousembodiments. For example, although the present disclosure refers tothree-dimensional computer models, it is envisioned that any of thecomputer models described in the present disclosure can betwo-dimensional. It should be further appreciated that the features andstructures described and illustrated in accordance with one embodimentcan apply to all embodiments as described herein, unless otherwiseindicated. Additionally, it should be understood that the conceptsdescribed above with the above-described embodiments may be employedalone or in combination with any of the other embodiments describedabove.

1. A method of pre-operatively forming a surgical splint configured toreceive a patient's dentition when the patient's skull is in apost-operative shape, the method comprising: obtaining a 3-D facialcomputer model in a computer of at least the patient's maxilla,mandible, and dentition, the 3-D facial computer model including firstvirtual dentition, wherein at least a portion of the first virtualdentition has a first virtual surface geometry that defines at least onefirst fiduciary marker, the at least one first fiduciary marker defininga first location that identifies a first anatomical feature of the firstvirtual dentition; obtaining a 3-D optical scan of the patient'sdentition in the computer, the 3-D optical scan including second virtualdentition, wherein at least a portion of the second virtual dentitionhas a second surface geometry that defines at least one second fiduciarymarker, the at least one second fiduciary marker defining a secondlocation that identifies a second anatomical feature of the secondvirtual dentition; aligning the first fiduciary marker with the secondfiduciary marker; and after the aligning step, replacing the firstvirtual dentition of the 3-D facial computer model with the secondvirtual dentition to form a composite 3-D virtual model, the composite3-D virtual model having third virtual dentition in a plannedpost-operative configuration.
 2. The method of claim 1, wherein the stepof obtaining the 3-D optical scan of the patient's dentition comprises astep of intraorally imaging the patient's dentition.
 3. The method ofclaim 1, wherein the step of obtaining the 3-D optical scan of thesurface geometry of the patient's dentition comprises a step of imaginga negative impression of the patient's dentition.
 4. The method of claim1, comprising, after the replacing step, displacing the third virtualdentition into the planned post-operative configuration.
 5. The methodof claim 4, wherein the third virtual dentition includes maxillarydentition and mandibular dentition, and the displacing step comprisesdisplacing one of the maxillary dentition and the mandibular dentitionwithout displacing the other of the maxillary dentition and themandibular dentition.
 6. The method of claim 1, wherein the firstvirtual dentition defines at least three first fiduciary markers, andthe second virtual dentition defines at least three second fiduciarymarkers
 7. The method of claim 1, wherein the step of obtaining a 3-Dfacial computer model comprises scanning the patient's skull with a CTscanner.
 8. The method of claim 1, wherein the composite 3-D virtualmodel includes a virtual maxilla and a virtual mandible, and the methodfurther comprises a step of manipulating the composite 3-D virtual modelinto the post-operative configuration by repositioning at least one ofthe virtual maxilla and the virtual mandible.
 9. The method of claim 1,further comprising a step of creating a virtual surgical splint model tomatch the third virtual dentition.
 10. The method of claim 1, whereinthe step of aligning the first fiduciary marker with the secondfiduciary marker is accomplished without the use of metal fiduciarymarkers.
 11. The method of claim 1, wherein the third virtual dentitionis identical to the second virtual dentition.
 12. The method of claim 1,wherein the second virtual dentition more accurately depicts thepatient's actual dentition than the first virtual dentition.
 13. Amethod of pre-operatively forming a surgical splint configured toreceive a patient's dentition when the patient's skull is in apost-operative shape, the method comprising: obtaining a virtualsurgical splint model that is formed by: obtaining a 3-D facial computermodel in a computer of at least the patient's maxilla, mandible, anddentition, the 3-D facial computer model including first virtualdentition, wherein at least a portion of the first virtual dentition hasan anatomical feature that defines at least one first fiduciary marker;obtaining a 3-D optical scan of the patient's dentition in the computer,the 3-D optical scan including second virtual dentition, wherein atleast a portion of the second virtual dentition has a second anatomicalfeature that defines at least one second fiduciary marker thatcorresponds to the first anatomical feature; aligning the firstfiduciary marker with the second fiduciary marker; after the aligningstep, replacing the first virtual dentition of the 3-D facial computermodel with the second virtual dentition to thereby form a composite 3-Dvirtual model having third virtual dentition; and creating the virtualsurgical splint model to match the third virtual dentition; andconstructing the surgical splint to correspond to the virtual surgicalsplint model.
 14. The method of claim 13, wherein the 3-D facialcomputer model is obtained by scanning the patient's skull with a CTscanner.
 15. The method of claim 13, wherein the composite 3-D virtualmodel includes a virtual mandible and a virtual maxilla, and thecomposite 3-D virtual model is manipulated by repositioning at least oneof the virtual maxilla and the virtual mandible.
 16. The method of claim13, wherein the first fiduciary marker is aligned with the secondfiduciary marker is accomplished without the use of metal fiduciarymarkers.
 17. The method of claim 13, wherein the third virtual dentitionis identical to the second virtual dentition.
 18. The method of claim13, wherein the step of obtaining the 3-D optical scan of the patient'sdentition in the computer comprises a step of imaging dental impressionsof the patient's dentition.
 19. The method of claim 13, wherein the stepof obtaining the 3-D optical scan of the patient's dentition in thecomputer comprises obtaining a 3-D optical intraoral scan of thepatient's dentition in the computer.
 20. The method of claim 13, whereinthe composite 3-D virtual model is manipulated into a plannedpost-operative configuration before creating the virtual surgical splintmodel.